1. Field of the Invention
This invention relates generally to an apparatus for selectively and covertly identifying and communicating with others. More particularly, this invention is directed to a portable apparatus which utilizes a directionally selectable infrared transmitter and receiver assembly for covertly communicating among friendly forces in a military and/or battlefield environment.
2. Description of the Prior Art
A constant concern for individuals engaged in combat is that they might be mistaken for the enemy by their compatriots, and as a result be injured or killed by what is commonly referred to as "friendly fire". In the past, given the technical limitations of weaponry, and the commensurate contained nature of the battle arena, solutions to the potential problem of misidentification were relatively simple.
As the battlefield has spread beyond the visual field and fighting continued into the night, however, the use of such simple devices for identifying friend or foe (IFF devices) as different colored uniforms, equipment, or flags has become ineffective. Modern technologies of war, which permit long range missile assaults and gun battles carried out between tanks and artillery units positioned miles apart, and common sourcing of machines of war, has required the fabrication of more reliable identification means. Unfortunately, the most relied upon means has remained knowing, relaying, and coordinating relative positions of troops by a central command center. A serious inherent weakness of such a system is that forces have to rely on a remote and delayed identification process which is often too slow to respond to an immediate threat or rapidly advancing forces. In addition, with modern radio source identification means, the means by which information is requested from a central command center, by soldiers in the field, often results in the revelation of the soldiers' position.
While it is always the case that the effective use of troops in the field of combat (as well as the skies above) is linked to the command structure, as troop strengths are spread out across larger and larger distances a system based on a command center for identifying other units encountered in the field means that the loss of a command post could render the troops without knowledge of who is friend and who is foe. Established procedures for such contingencies exist, but they often include radio transmissions. This, again, is generally less desirable because field radio transmissions, which are broadcast further and through 360 degrees, may be monitored, jammed, or used in other ways by the enemy to locate the transmitting soldier or soldiers.
In the prelude to the Gulf War, in which a multiplicity of countries were being massed to form a coalition force, with a variety of disparate forces to be led by a unitary command, the U.S. military began searching for a more reliable IFF system to ensure safety from friendly fire casualties. The most popular device which was proposed, and which was ultimately utilized, consisted of an array of infrared emitting LEDs which provided a constant or rhythmic flash beacon through a full 360 degree field. By placing these devices, which were euphemistically referred to as "Budlites", on tanks, helicopters, and other units, it was possible for individual coalition force units to make autonomous on-site identification of forces which it encountered.
The Budlite system is, however, a crude fix for a complex problem. It is easily understood how such a system could provide an easy target acquisition beacon for a prepared enemy. In addition, despite the fact that the Iraqi forces were entirely unequipped to take advantage of this flaw, fully 25 percent of the casualties incurred by the coalition forces was attributed to friendly fire. On several occasions, the failure of a Budlite element to function properly caused the unit using the faulty element to be confused for an Iraqi force, and to become an unfortunate target when the coalition force viewing them relied too heavily on the missing infrared beacon.
More sophisticated IFF systems, including those integrated with laser targeting and designation devices carry considerable risks of cornea damage to the users. In severe cases retina damage may also result. With added gain in incident light energy associated with the focusing effects of binoculars, radiation damage to the eyes of users can occur even with so-called "eye safe lasers".
It is, therefore, an object of the present invention to provide an IFF device which is portable and decouples the troop identification process from a centralized location.
It is, also, an object of the present invention to provide an IFF device which obviates the need for radio transmissions which could be intercepted, jammed, or otherwise compromised during the course of battle.
It is, further, an object of the present invention to provide a covert IFF device which is selective in its signal transmission so as to minimize the risk that an enemy could identify or locate its source while it is being used.
It is also an object of the present invention to provide a fully eye safe IFF device which may be used to both identify a friendly element in a battlefield environment as well as to communicate information covertly.